The present invention relates to a radiation image information processing system, and more particularly to a radiation image information processing system for reading radiation image information from a stimulable phosphor sheet, and processing the read-out radiation image information to record it on a film or display it on a CRT or the like, and simultaneously to record image data representing the radiation image information and retrieval data thereof on an randomly accessible recording medium.
There has been developed a radiation image recording and reproducing system for producing a radiation transmitted image of an object using a stimulable phosphor sheet. Many patent applications have been filed in relation to the developed radiation image recording and reproducing system (see, for example, Japanese Laid-Open Pat. Publications Nos. 55-12429, 55-103472, 55-116340, and 55-8797). The radiation image recording and reproducing system has found wider use particularly in the medical field. When a certain phosphor is exposed to a radiation such as X-rays, .alpha.-rays, .beta.-rays, .gamma.-rays, cathode rays, or ultraviolet rays, the phosphor stores a part of the energy of the radiation. When the phosphor exposed to the radiation is subsequently exposed to stimulating rays such as visible light, the phosphor emits light in proportion to the stored energy of the radiation. The phosphor exhibiting such a property is referred to as a "stimulable phosphor".
In the radiation image recording and reproducing system employing such a stimulable phosphor, the radiation image information of an object such as a human body is stored in a sheet having a layer of stimulable phosphor, and then the stimulable phosphor sheet is scanned with stimulating rays such as a laser beam to cause the stimulable phosphor sheet to emit light representative of the radiation image. The emitted light is then photoelectrically detected to produce an image information signal that is electrically processed for generating image information which is recorded on a recording medium such as a photographic photosensitive material or displayed as a visible image on a CRT or the like.
It has been general practice in the medical field to record radiation image information on an X-ray film. Since an X-ray film with radiation image information recorded therein is legally required to be kept for a certain period of time, the number of X-ray films kept in a medical facility such as a hospital is considerably large. Therefore, medical facilities with a radiographic system have to have a space large enough to keep such X-ray films. Measures must also be taken to shield stored X-ray films from moisture and extraneous light in order to keep them in a good condition over a long period of time.
Adequate medical diagnosis requires quick access to a particular X-ray film containing image information. However, it takes quite a long time to manually pick up a certain X-ray film from a vast number of stored X-ray films. This is particularly problematic when an emergency need arises for an exposed X-ray film for use in an operation, for example, because the time-consuming manual retrieval procedure might result in a serious accident.